Abstract: This multi-cylinder internal combustion engine (1) is provided with an EGR device (30) containing an EGR cooler (27), a valve overlap period in which valve opening periods of intake valves (20) and exhaust valves (21) overlap one another is set, and the multi-cylinder internal combustion engine (1) has four cylinders (2). The multi-cylinder internal combustion engine (1) comprises: four exhaust side branch conduits (15), one provided for each of the cylinders (2); a storage tank (31) configured to store condensed water (CW) generated by the EGR cooler (27); and four condensed water introduction conduits (33), one provided for each of the exhaust side branch conduits (15) and communicating the exhaust side branch conduit (15) with the storage tank (31).

Abstract: An ECU 70A is applied to an internal combustion engine 50 of in-cylinder injection type equipped with a fuel injection valve 56 that injects fuel into a combustion chamber E, an intake valve 54 and an exhaust valve 55 provided for the combustion chamber E, and VVTs 57 and 58 that cause the intake valve 54 and the exhaust valve 55 to overlap each other. In a case where the VVTs 57 and 58 cause the intake valve 54 and the exhaust valve 55 to overlap each other to thereby scavenge the combustion chamber E, the ECU 70A sets the injection pressure of fuel injected by the fuel injection valve 56 lower than that for a case where the intake valve 54 and the exhaust valve 55 are not caused to overlap each other.

Abstract: A combustion chamber structure for an internal combustion engine includes, in a piston top part, a concave portion formed eccentrically with respect to a cylinder center axis, and a tapered portion that connects an upper end face of the piston top part and a side face of the concave portion. The tapered portion is formed so that a tapered portion volume (volume of a space formed between the tapered portion and an upper wall surface of the combustion chamber) in a first portion of the piston top part is greater than a tapered portion volume in a second portion that is nearer than the first portion to an eccentric direction of the concave portion from the cylinder center axis.

Abstract: An ECU 70A is applied to an internal combustion engine 50 of in-cylinder injection type equipped with a fuel injection valve 56 that injects fuel into a combustion chamber E, an intake valve 54 and an exhaust valve 55 provided for the combustion chamber E, and VVTs 57 and 58 that cause the intake valve 54 and the exhaust valve 55 to overlap each other. In a case where the VVTs 57 and 58 cause the intake valve 54 and the exhaust valve 55 to overlap each other to thereby scavenge the combustion chamber E, the ECU 70A sets the injection pressure of fuel injected by the fuel injection valve 56 lower than that for a case where the intake valve 54 and the exhaust valve 55 are not caused to overlap each other.